Abstract
Effects of ionic surfactants on the amperometric response of Fe(CN)3-6 at a gold electrode modified with the self-assembled monolayer (SAM) of an alkanethiol were examined in a flow system using an aqueous solution of a supporting electrolyte as the mobile phase. The response was enhanced by a cationic surfactant but depressed by an anionic surfactant, being detected as a positive and a negative peak, respectively. Octyl- and decylthiol were suited for the electrode modifier, and LiCl or NaCl was the electrolyte of choice. With 5% aqueous MeOH containing NaCl (0.1M) and K3Fe(CN)6 (5mM) as the mobile phase, the amperometric peak area was linearly correlated with the concentration of surfactants, indicating that the SAM-modified electrode is a prospect as a detector for surfactants in high-performance liquid chromatography.
